Volatile Anesthetics Don't Improve Outcomes for Coronary Artery Bypass

Giovanni Landoni, MD

Patients undergoing coronary artery bypass grafting (CABG) procedures do not appear to benefit from the use of volatile anesthetics instead of total intravenous anesthesia, according to a new study.

Volatile anesthetics, which are inhaled, have been shown in several studies to have cardioprotective effects on patients. An international team of researchers wanted to see if the use of these anesthetics as part of a patient’s anesthesia might therefore lead to better outcomes in patients who undergo the procedure.

The investigators assembled 5400 patients, assigning half of them (2709) to receive volatile anesthetics as part of their anesthesia, and assigning the other 2691 to a total intravenous anesthesia group. About two-thirds (64%) of the patients in the study underwent on-pump CABG procedures, and mean length of time of cardiopulmonary bypass was 79 minutes. The primary outcome was death of any cause at 1 year.

The results showed volatile anesthetics had no significant effect. Patients who received the volatile anesthetics had an all-cause death rate of 2.8% at 12 months. Those who received total intravenous anesthesia had a death rate of 3.0%.

“Volatile agents, used as they are used in clinical practice, do not reduce 1-year mortality in elective isolated CABG,” said corresponding author Giovanni Landoni, MD, of Vita-Salute San Raffaele University, in Italy. “This is definitive.”

Landoni and colleagues also wrote that the odds of death at 30 days were similar between the 2 groups, as were the adverse event profiles.

In finding no benefit to volatile anesthetics, Landoni and colleagues differed from other studies. One difference between this study and earlier research was the inclusion of off-pump CABG patients in the data. However, Landoni and colleagues wrote that a pre-specified subgroup analysis found there was no variance in outcomes in the primary outcome in on-pump versus off-pump procedures.

Another factor that might have affected the outcome is the coadministration of propofol during induction of anesthesia. There has been conflicting evidence about what effect propofol might have on patient outcomes and on the cardioprotective benefits of volatile anesthetics. Landoni said that question is worthy of further study.

“Of course there is the possibility to further investigate this field, but you have to introduce something that differs from the routine clinical practice,” he told MD Magazine®. “One clever possibility is to completely avoid the use of propofol.”

Landoni cautioned, though, that such a study would take time.

“Unfortunately, with all the bureaucracy and stupid costs that burden academic, collaborative research, it will take years before answering other questions,” he said.

In the meantime, he said there are still plenty of uses for volatile anesthetics.

“Volatile anesthetics are excellent general anesthetics and most anesthesiologists are using and will go on using them,” he said.

Landoni and colleagues also noted that their study was specifically focused on patients undergoing isolated elective CABG. It’s possible that volatile anesthetics would still benefit patients undergoing more complex surgeries.

The study, “Volatile Anesthetics versus Total Intravenous Anesthesia for Cardiac Surgery,” was published in the New England Journal of Medicine.